When your best theory to explain anomalies is “hit by an asteroid”, your guess work is lacking in explanatory power. Eric Falkenstein has a laugh out loud post on current hypotheses for planetary behavior:
While economists have been taking a beating for not predicting the future correctly, it is useful to remember that when you take a physicist to the real world, he too has little to say. Consider our understanding of our solar system, a seemingly straightforward issue.
Mercury: Has an abnormally large iron core. For its size, its density seems too high. This is a puzzle. Leading theory: hit by asteroid.
Venus: Venus rotates in a clockwise fashion, in contrast to other planets. Leading theory: an asteroid hit it to spin the other way
Earth: No one knows where the water came from. Leading theory:snow comets hit us. The moon’s origin, also, is not obvious, because it doesn’t have enough iron, and if it just spun out of a really fast spinning earth, the earth would still be spinning fast or the energy release needed to slow the earth down would raised the temperature to 1000 degrees Celsius. Nebula forming two planets, or planetary capture, don’t work. Leading theory: an asteroid hit the early Earth,creating the moon.
You’d think it ends there, but no, the asteroids keep on hittin’. Read the whole thing. Falkenstein omits one leading theory for the origins of life on earth as well. The theory? You guessed it: hit by an asteroid. Humph…